ICD-10 Code D51.9 – Vitamin B12 Deficiency Anemia, Unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D51.9 – Vitamin B12 deficiency anemia, unspecified
What it is
D51.9 identifies anemia caused by vitamin B12 deficiency when the record does not specify the exact type. Use it for B12-related anemia with incomplete documentation.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include anemia with symptoms such as fatigue, pallor, or weakness, and evidence supporting vitamin B12 deficiency.
When to use this code
Use D51.9 when the provider documents vitamin B12 deficiency anemia but does not name a more specific subtype. It also fits cases where the chart confirms B12 deficiency anemia without additional detail needed for a more precise code.
Do not use for
Do not use this code for anemia due to folate deficiency, other nutritional anemias, or anemia without documented B12 deficiency. Check documentation if the cause is unclear.
Coding tip
If the note names a specific B12 deficiency anemia type, code that more specific diagnosis instead of D51.9.